3J21 Constant Elasticity Alloy Wire, Precision Micro-wire for Instrumentation

Professional supplier of 3J1 constant elasticity alloy fine wire with low elastic modulus temperature coefficient and dimensional tolerance of ±0.005mm.

Material Overview

3J21 is a cobalt-based constant-elasticity alloy wire with excellent elastic properties and dimensional stability. Its modulus of elasticity has an extremely low temperature coefficient, changing by less than 0.01% between -50°C and +100°C, making it an ideal material for precision elastic components.

3J21 alloy wire is produced via vacuum induction melting, followed by multi-pass cold drawing and aging treatment to ensure uniform microstructure and consistent mechanical properties. Its high surface finish and non-magnetic characteristics make it ideal for precision instruments sensitive to magnetic fields.

Chemical Composition and Mechanical Properties

Chemical Composition of 3J21 Alloy Wire (Mass Fraction %)

ElementContent Range
CoRemaining
Cr19.0-21.0
Hi9.0-11.0
Mo6.0-8.0
It1.8-2.2
C≤0.08
Fe≤1.00

Mechanical Properties of 3J21 Alloy Wire

Tensile Strength

≥1100 MPa

Yield Strength

≥650 MPa

Elongation

≥10%

Density

8.35 g/cm³

Temperature Coefficient of Elastic Modulus

<0.01%/°C (-50~100°C)

Available Wire Specifications

Wire diameter range

0.08mm - 2.0mm

Delivery Status

Hard-drawn (cold-drawn) / Annealed

Packaging Format

Coiled / Straight (Cut-to-Length)

Execution Standard

GB/T 15018

Core Product Advantages

Excellent constant elasticity performance

The temperature coefficient of the elastic modulus is extremely low, ensuring stable elastic performance across a wide temperature range.

Non-magnetic

Completely non-magnetic; ideal for precision instruments and electronic devices sensitive to magnetic fields.

Excellent corrosion resistance

Cobalt alloy properties provide excellent resistance to acid and alkali corrosion.

High dimensional accuracy

Wire diameter tolerance controlled within ±0.005mm, meeting precision component manufacturing requirements.

Industries

  • Precision instrument elastic sensitive elements, diaphragms, and bellows
  • sensor springs, resonators, delay lines
  • Precision Elastic Components for Medical Devices
  • Elastic components for precision instruments in aerospace

Processing & Delivery

Complementary Services

  • Wire straightening
  • Custom Slitting to Length
  • Provide 3.1 material certification
  • Technical Support & Material Selection Consultation

Delivery Timeline

Standard specifications in stock; ships in 3-5 business days. Custom special specifications require production; lead time is 7-15 business days. Nationwide delivery supported; expedited service available.

Frequently Asked Questions (FAQ)

What precision components is 3J21 elastic wire suitable for manufacturing?

3J21 constant-elasticity alloy wire is ideal for manufacturing elastic sensitive components, diaphragms, bellows, sensor springs, resonators, and delay lines in precision instruments. Its constant elasticity and non-magnetic properties make it a perfect material for high-precision measuring devices.

What is the heat treatment process for 3J21 wire?

3J21 wire typically undergoes a heat treatment process consisting of solution treatment followed by aging. The solution treatment temperature is approximately 1150°C, and the aging temperature ranges from 600 to 700°C. Soaking time is adjusted based on wire diameter. Proper heat treatment is critical for achieving consistent elastic properties.

What is the minimum wire diameter available for 3J21 alloy wire?

3J21 alloy wire is available with a minimum diameter of 0.08mm, meeting the manufacturing requirements for precision elastic components and micro springs. Wire diameter tolerance is controlled within ±0.005mm, and surface finish achieves Ra ≤ 0.4 μm.

What is the modulus of elasticity for 3J21 wire?

The elastic modulus of 3J21 alloy wire is approximately 200-220 GPa, and its variation rate within the temperature range of -50°C to +100°C is less than 0.01%. This is a core characteristic that makes it an invariant elasticity alloy.

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